1. Field of the Invention
In an angled bulldozer blade and tractor combination having a C-frame and, in particular, an improved connection between the two halves of the C-frame.
2. Description of the Prior Art
At one time, and for certain applications even today, C-frames are constructed substantially of one piece. This has resulted in problems in shipment of the C-frame and in manufacturing the C-frame in such a way that the trunnion mountings at each end of the arms of the C-frame are in a common plane for attachment to the tractor. An improvement was adopted sometime ago wherein the C-frame was broken just to the right or to the left of the midportion of the C-frame and flanges were fixed on the opposite ends of the two halves of the C-frame which could then be bolted together for use or unbolted for storage and shipment. This had a disadvantage in that the holes in the respective flanges had to be carefully aligned with the reference points for the trunnion mountings at the ends of the arms to be sure that the C-frame, when assembled, could be assembled to the tractor. The C-frame with the flanged and bolted halves must be taken apart for shipment and reassembled in the field. The bolted joint causes manufacturing problems in that the holes for the joint must be aligned in both halves so that when they are bolted together the dimension across the ends of the arms of the C-frame is fixed and must match the tractor. In order to ensure a good joint, all of the bolts must be kept tight and where the bolts are put in in the field, it is almost impossible to ensure proper installation torques. Also, since the C-frame is, in effect, one piece after being bolted together, the sharing of side loads from left to right or from right to left is not positive.
In an attempt to provide a means for positively aligning the two halves of the C-frame, structure has been proposed whereby tapered shear sleeves are bridged across the juncture between the two halves prior to bolting the two halves together which, presumably, better aligns the two halves and provides a stronger sheer plane between the two halves. This is relatively expensive, requires very accurate machining and still does not assure that the spacing between the halves will be accurate or that the planes of the two halves will coincide with the mounting.
A pivot mounting between the two halves has been proposed whereby the pin for mounting the blade to the C-frames is connected directly to the spacer between the two halves and surrounding the pivot pin. This device has the disadvantage that for shipment, the pin is removed and must be stored separately which always raises the possible problem of losing the pin. Secondly, this construction provides for the blade lift connection being an integral part of the joint between the two halves of the C-frame. This reduces the flexibility of the connection between the two halves of the C-frame, and requires added space between the tractor and the C-frame for the connection for the lift arrangement. In addition, the trunnion mounting for the lift assembly is a loose item which must be disassembled and stored separately when the two halves of the trunnions are separated. Also, with the trunnion mounted between the two halves at the pivot connection of the C-frame, the two halves of the C-frame cannot be easily adjusted to fit the mounting on the track roller frame.